It’s a good thought because let’s face it in the beginning Japanese offense is supplied solely through air… i wouldn’t though and i’ll give my reasons:
First, it’s five IPCs that means another infantry and in the beginning Russia needs every INF that she can get a hold of. And really, in turn 1 it costs Russia effectively 2 INF because instead of standard 8 INF buy she would only be able to do 6 INF + AA gun so you really lose 2 INF. That can make a big difference this early in the game.
Second, as TG Moses VI said the odds aren’t with you on any single attack… I would say unless Japan massed air but usually it’s just 1 fighter here, 2 there, maybe 1 fighter and a bomber… but if they were to send say 4 air on one attack then maybe it could be justified for that battle alone…
Third unless you’re playing with scorched earth if Japan gets it it’s a free AA gun they can put down in Manch or India or wherever they have an IC. Though this latter is kind of an after-the-fact issue.
It’s an interesting thought but I think on R1, R2 especially you want every single possible INF you can get… at least that’s my thought on the issue.
If you do play that scenerio one time do post and let us know how it turned out.